Filter apparatus for semiconductor device fabrication process

Abstract

A filter device includes one or more filter membranes, and a filter housing enclosing the one or more filter membranes. Each of the filter membranes includes a base membrane made of a ceramic material, and a plurality of through holes. The base membrane is coated with a coating material.

What is claimed is: 
     
       1. A filter device used in an apparatus for manufacturing a semiconductor device, comprising:
 one or more filter membranes; and 
 a filter housing enclosing the one or more filter membranes, 
 wherein each of the one or more filter membranes includes a base membrane made of a ceramic material, and a plurality of through holes, 
 the base membrane is coated with a coating material, 
 an average diameter of the plurality of through holes is in a range from 10 nm to 500 nm, and 
 a variation of diameters of the plurality of through holes is in a range from 5% to 25% of the average diameter. 
 
     
     
       2. The filter device of  claim 1 , wherein the average diameter of the plurality of through holes is in a range from 50 nm to 200 nm. 
     
     
       3. The filter device of  claim 2 , wherein the variation of diameters of the plurality of through holes is in a range from 10% to 20% of the average diameter. 
     
     
       4. The filter device of  claim 1 , wherein a thickness of the base membrane is in a range from 50 nm to 500 nm. 
     
     
       5. The filter device of  claim 1 , wherein an aspect ratio of the plurality of through holes is in a range from 2 to 10. 
     
     
       6. The filter device of  claim 1 , wherein the coating material includes one or more of a PE (polyethylene), a PTFE (polytetrafluoroethylene), a PVDF (polyvinylidene fluoride), a PFA (polyfluoroalkoxy), a HDPE (high density polyethylene), a PAS (polyarylsulfone), a PES (polyether sulfone), a PS (polysulfone), a PP (polyproplyene) and a PEEK (polyetheretherketone), or derivatives thereof. 
     
     
       7. The filter device of  claim 1 , wherein the ceramic material is anodic aluminum oxide. 
     
     
       8. The filter device of  claim 1 , wherein a total number of the plurality of through holes per square micron is in a range from 100 to 600. 
     
     
       9. The filter device of  claim 1 , wherein the one or more filter membranes comprises two or more filter membranes having different average hole sizes from each other. 
     
     
       10. The filter device of  claim 9 , wherein:
 the filter housing includes an inlet and an outlet, and 
 a filter membrane of the two or more filter membranes having a larger average hole size is located closer to the inlet than a filter membrane of the two or more filter membranes having a smaller average hole size. 
 
     
     
       11. A liquid supplying system comprising:
 a semiconductor wafer processing apparatus; 
 a liquid tank configured to store a liquid for manufacturing a semiconductor device; 
 a liquid supply system for supplying the liquid from the liquid tank to the semiconductor wafer processing apparatus; and 
 a point-of-use (POU) filter device disposed on the liquid supply system, 
 wherein the POU filter device includes:
 one or more filter membranes; and 
 a filter housing enclosing the one or more filter membranes, 
 
 each of the filter membranes includes a base membrane made of anodic aluminum oxide, and a plurality of through holes, 
 the base membrane is coated with a coating material, 
 an average diameter of the plurality of through holes is in a range from 10 nm to 500 nm, and 
 a variation of diameters of the plurality of through holes is in a range from 5% to 25% of the average diameter. 
 
     
     
       12. The liquid supplying system of  claim 11 , wherein the average diameter of the plurality of through holes is in a range from 50 nm to 200 nm. 
     
     
       13. The liquid supplying system of  claim 12 , wherein the variation of diameters of the plurality of through holes is in a range from 10% to 20% of the average diameter. 
     
     
       14. The liquid supplying system of  claim 11 , wherein a thickness of the base membrane is in a range from 50 nm to 500 nm. 
     
     
       15. The liquid supplying system of  claim 11 , wherein the coating material includes one or more of a PE (polyethylene), a PTFE (polytetrafluoroethylene), a PVDF (polyvinylidene fluoride), a PFA (polyfluoroalkoxy), a HDPE (high density polyethylene), a PAS (polyarylsulfone), a PES (polyether sulfone), a PS (polysulfone), a PP (polyproplyene) and a PEEK (polyetheretherketone), or derivatives thereof. 
     
     
       16. The liquid supplying system of  claim 11 , wherein the semiconductor wafer processing apparatus is a chemical mechanical polishing (CMP) apparatus, and the liquid is a CMP slurry. 
     
     
       17. The liquid supplying system of  claim 11 , further comprising a circulation path for circulating the liquid from the liquid tank to the liquid tank,
 wherein the circulation path includes another filter device. 
 
     
     
       18. A method of cleaning a filter device, comprising:
 determining whether the filter device is to be cleaned or not; and 
 after determining that the filter device is to be cleaned, flowing a cleaning solution through the filter device in a reverse direction, 
 wherein the filter device includes:
 a filter membrane; and 
 a filter housing enclosing the filter membrane, 
 
 the filter membrane includes a base membrane made of anodic aluminum oxide, and a plurality of through holes, 
 the base membrane is coated with a coating material, 
 an average diameter of the plurality of through holes is in a range from 10 nm to 500 nm, and 
 a variation of diameters of the plurality of through holes is in a range from 5% to 25% of the average diameter. 
 
     
     
       19. The method of  claim 18 , wherein the determining comprises:
 monitoring a flow rate of a liquid passing through the filter device; and 
 determining whether the flow rate is below a threshold rate. 
 
     
     
       20. The method of  claim 18 , wherein the cleaning solution is water or an organic solvent.